At right, coffee cake purchased at Starbucks: $1.95
Wilbur's recipe made twelve squares. So: 36 cents a piece for homemade, which was tender and buttery, if a bit messy to cut. Starbucks coffee cake was tidy and rigid and the topping tasted very slightly rancid.
No smug lectures. I understand why people buy Starbucks coffee cake. I've done it myself and will do it again. But if you ever think it's "not bad" you need to make Wilbur's clone recipe -- or any coffee cake recipe -- and taste side by side. It's pretty bad and they're not giving it away.
Interesting fact: Most expensive single component of homemade coffee cake is butter, followed by vanilla. Everything else is almost trivial.